The existing motor having a structure in which a conductive part called a bus bar is disposed above a coil and the coil is electrically connected to an external power supply through the conductive part has been known. Generally, the bus bar is connected to a plurality of coils arranged in an annular shape and therefore may be mainly formed in an annular shape or an arch shape. However, when a copper plate as a raw material is subject to punching process with a press machine into an annular shape or an arc shape, a lot of wasteful portions may occur in the copper plate and a yield of the material may be aggravated.
In this respect, Japanese Patent Publication No. 3717832 discloses that a bus bar is manufactured by punching a conductive metal plate member, such as a copper plate or the like, with a press machine into a stripe shape and bending the stripe-shaped preformed material in a thickness direction. The Japanese Patent No. 3717832 discloses that the yield rate can be improved by punching the stripe-shaped preformed materials in parallel.
However, in the specification of Japanese Patent No. 3717832, a plurality of tabs protrude from a substantially C-shaped bus bar. These tabs are formed in the conductive metal plate simultaneously when the conductive metal plate is punched by the press machine. Therefore, the bus bars and the tabs are integrally formed in the state in which they are connected to each other by going through a one-time pressure process.
As such, in the structure of the specification of Japanese Patent Publication No. 3717832, with a plurality of tabs, the shape of the stripe-shaped material punched in the press process becomes complicated. For this reason, a wasteful portion still remains in the conductive metal plate. To reduce manufacturing costs of the motor, there is a need to further increase the yield of the material.
However, when the bus bar unit including the plurality of bus bars is used, there is a need to suppress the overall size of the bus bar unit while preventing these bus bars from being in contact with each other. That is, a structure capable of increasing the yield of the material and suppressing the size of the bus bar unit is required.